top off water

[thien]

Hi,

I've read here and there that top off water should be buffered. Is it not a good idea to simply pour fresh, temperature-matched RO water into the tank?

Thanks.
Thien

[john rock]

I've heard some people do this but I've never bothered. I find it doesn't make a dif.

[ALRHA]

i think you may be confused with those who add buffer as their top-off as in those who add all their top-off in the form of Calcium Hydroxide (Kalkwasser). I plan to be one of 'those' as soon as my doser and pH probe come in on thursday. -WooHoo!

[john rock]

no I believe[and I could be wrong] that THEIN was talking about the practise of matching your fresh water ph to your tank ph. Some people do this as well as add buffer to there tank later and/or kalk. Some people believe that freshwaters ph which is usually lower than what we strive for[8.1 or so] will drag the ph of the tank down but I've never bothered and it never has.

[thien]

yup, johnny's got my question right. I read that people put in baking soda (?) to raise PH in their top off water. I was just wondering if the extra work was necessary.

thanks.

[ALRHA]

i stand corrected - sorry

[GoSUV]

Some people put baking soda into their top off water to prevent wild pH swings, that's understandable, but it works only for fish only tanks where you don't care about Calcium levels. Baking soda has only the alk portion which will cause a alk/Ca imbalance if you don't dose Calcium-only supplements in an equal proportion.

The best solution [no pun] is to dose kalk which is naturally balanced.

The fresh water top off, even with a neutral pH of 7, won't cause your tank pH to drop too much. At least not with the amount we put in. The alk reserve in your tank water should be able to handle that. That's what keeping up alk is for. You should be more concerned about the SG rising too high for NOT toping off with freshwater.